The present invention relates to an IC component-mounting method and apparatus preferably applicable in directly mounting an IC component, in particular, a flip chip or IC components on a circuit board or circuit boards.
The conventional method for mounting the IC component on the circuit board comprises the steps of supplying the IC component having a lead projecting from a side face thereof and accommodated in a package to a supply position; sucking the IC component at the supply position by a mounting head; recognizing the image of the posture of the sucked IC component by a component-recognizing portion; mounting the IC component on a mounting position of the circuit board by correcting the posture of the IC component being sucked by the mounting head; and soldering the lead of the IC component to an electrode of the circuit board.
Flip chip bonding is known as a method to replace wire bonding. In the flip chip bonding, an electrode of the flip chip is bonded to an electrode of an insulation board after the flip chip is mounted on the insulation board by turning an electrode-provided surface downward.
In recent years, in order to develop compact electronic equipments having high functions, there is a growing demand for the development of highly integrated and compact IC components. Hence, the recent tendency is to install many pins on the circuit board and IC components thereon at small pitches. It is conceivable to mount the flip chip IC directly on the circuit board as a method for manufacturing super-compact electronic equipments such as portable telephones or pocket word processors. In carrying out this method by utilizing the above-described conventional mounting method, it is necessary to supply the flip chip IC to the supply position by turning a bonding electrode-provided surface thereof downward (face-down). Consequently, in transporting the flip chip IC accommodated in a tray in the face-down posture, there is a possibility that bumps formed on the electrodes of the flip chip IC are damaged during transport and that hence an appropriate bonding state cannot be obtained on the circuit board after the flip chip IC is mounted on the circuit board. In order to overcome this problem, the flip chip IC is transported by accommodating them in a transport tray in the face-up state. In mounting the flip chip IC, it is taken out from the transport tray manually and accommodated in a mounting tray in the face-down state. This method has a low productivity and is incapable of solving the above-described problem because the flip chip IC is accommodated in the mounting tray in the face-down state.
In sucking the flip chip IC at the supply position by the sucking nozzle, there is a problem in that the sucking nozzle collides with the face of the flip chip IC strongly, thus damaging the circuit of the flip chip. This occurs is because the sucking nozzle may contact bumps, thus damaging them; an appropriate sucking state cannot be obtained; or the sucking nozzle merely moves downward to a certain position during the sucking operation.
Because many of the circuit boards comprise a multilayer board made of glass epoxy resin, the entire board is wavy and slight inclinations are generated on the surface of the board at each mounting position thereof due to irregularities caused by a wiring pattern of an underlayer. In mounting the flip chip IC directly on such a circuit board, there occurs a problem in that the bump of the flip chip IC cannot be appropriately bonded to the electrode of the circuit board.
A pressure-controlling method or a heat-controlling method are employed to mount the flip chip IC directly on the circuit board. But these methods cannot be carried out by the conventional IC component mounting apparatus.
In addition, if the flip chip IC is mounted on the circuit board by making the reference side of a circuit board-regulating means stationary, the mounting position of the circuit board is dislocated from a correct mounting position due to thermal expansion thereof. Thus, the flip chip IC cannot be mounted on the circuit board with high accuracy.